1. Field of the Invention
This invention generally relates to a front derailleur for a bicycle. More specifically, the present invention relates a front derailleur mounting arrangement that mounts the front derailleur to a bottom bracket.
2. Background Information
Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle. The various components of the bicycle are usually mounted to the bicycle frame. Some components of the bicycle that have been extensively redesigned are the front derailleurs.
Generally, a front derailleur is typically secured to the seat tube of the bicycle frame and/or the bottom bracket of the bicycle. Basically, the front derailleur has a fixed member secured to the bicycle frame in a non-movable, and a movable member supported to be movable relative to the fixed member via a linkage mechanism. The movable member supports a chain guide having a pair of vertical surfaces for contacting a chain.
In recent years, bicycle frames have been provided with rear suspensions. As result of these rear suspensions, often the seat tube of the bicycle frame is removed or cut away to accommodate the rear suspension. In order to accommodate a seat tube type of rear derailleur mounting arrangement, a short seat tube must be left or added to the bicycle frame. However, in some instances it is not possible to add an additional piece of framing material where the seat tube is normally located. In such circumstances, a bottom bracket type of front derailleur mounting arrangement must be utilized. One problem with the bottom bracket type of front derailleur mounting arrangement is that it is sometimes difficult to install. In other words, the installer usually must hold the mounting bracket while installing the bottom bracket into the bottom bracket tube of the frame. Thus, the installer can only use one hand to thread the bottom bracket into the seat tube. This can be difficult since the bottom bracket is often installed utilizing a pneumatic tool that can be heavy and/or awkward to handle with one hand.
In view of the above, there exists a need for a front derailleur mounting arrangement which overcomes the above mentioned problems in the prior art. This invention addresses this need in the prior art as well as other needs, which will become apparent to those skilled in the art from this disclosure.
One object of the present invention is to provide a front derailleur mounting arrangement that aids in the mounting of the bottom bracket and the front derailleur to the bicycle frame.
Another object of the present invention is to provide a front derailleur mounting arrangement that relatively simple and inexpensive to manufacture and assembly.
The foregoing objects can basically be attained by providing a front derailleur mounting arrangement comprising a bottom bracket tube and a front derailleur mounting bracket. The bottom bracket tube has an interior threaded passage with a center axis and a first complementary mounting structure. The front derailleur mounting bracket includes a lower attachment portion with a bottom bracket opening and a second complementary mounting structure, and an upper derailleur support portion extending from the lower attachment portion. The upper derailleur support portion has a derailleur mounting part. One of the first and second complementary mounting structures is configured to form a slot and the other of the first and second complementary mounting structures is configured to form a projection. The projection mates with the slot to retain the front derailleur mounting bracket in a predetermined rotational orientation and a predetermined axial orientation on an axial end edge of the bottom bracket tube prior to threading of a bottom bracket within the interior threaded passage of the bottom bracket tube.
These and other objects, features, aspects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the present invention.